Zeta$^2$ Coronae Borealis, A Spectroscopic Triple System Including an Asynchronous Close Binary

Using the 1-m telescope at Ritter Observatory, we took 36 observations
of \zeta$^2$ Coronae Borealis with a fiber-fed echelle spectrograph.
From these observations, \zeta$^2$ CrB was found to be a triple system
and a new spectroscopic orbit was calculated. This orbit has two
periods, a 1.72357 day period for the inner binary composed of \zeta$^2$
CrB A $&$ B and a 251 day period for the outer binary compsed of
\zeta$^2$ CrB AB $&$ C. The inner binary is a double-lined
spectroscopic binary composed of two B7 V stars. The inner binary`s
center of mass (\zeta$^2$ CrB AB) describes a long-period single-lined
variation identified with the outer binary. The inner binary period is
significantly shorter than the 12.5842 day period previously calculated
by Abhyankar $&$ Sarma (1966). The inner binary possesses an
essentially circular orbit $(e = 0.48)$. From the widths of their Si II
6371 \AA lines, the \upsilon sin $i$'s were calculated to be 46 \pm 7 km
s$^-1$ for \zeta$^2$ CrB A and 7.5 \pm 2 km s$^-1$ for \zeta$^2$ CrB B.
As \zeta$^2$ CrB A $&$ B have similar masses, their different
rotational velocities make this system a sensitive test of
synchronization theories. (SECTION: Stars)